248 



PEOCEEDINGS OF THE GEOLOGICAL SOCIETY. [Jan. 24, 



In the first cave, which is established on a line of fracture of the 

 limestone, enlarged by the passage of water, the general order of the 

 accumulation which occupies the lower portion, is as follows (as 

 traced for me in my note-book by M. Dupont ; a layer of " argile 

 smectique " of M. Dupont, next to the limestone rock, is merely the 

 product of the decomposition of the impure hmestone) : — 



1. A thick accumulation of Hmestone talus, from the face of the 

 cliff. 



2. Loamy sand. 



3. Eounded quartz pebbles. 



Beds 2 and 3 extend back into the cave, sloping upwards. 



Fig. 3. — Section of the dejposits at the entrance of the Furfooz Cave. 



a. Angular debris — Argile a blocs anguleux. 

 h. Stalagmite. 



c. Sandy Clay. Bear and Eeindeer. 



d. Shingle — Cailloux Ardennais. 



e. Fluviatile sands. Beaver, &c. 



In the second cave, which is lower in the cliff, there is outside, 

 an accumulation of debris, beneath which, and passing into the 

 cave, are 



1. Sandy and marly beds, in which are a few angular blocks, 

 such as may have fallen from above whilst the bed was forming. 

 Lines of successive accumulation. 



2. Bed of quartz pebbles, in layers, sloping outwards. 



3. Sands, bedded, like river sand ; remains of beaver. 



The upper level of the pebbles in the second cave* is wholly below 

 that of the pebbles of the first cave ; this circumstance entirely dis- 

 connects the shingle from any alluvial action of the Lesse. Even 

 Avere the two accumulations at the same level, and had they been 

 lodged in these caverns by a river flowing down the valley at a very 

 high level, the arrangement of the pebbles would probably have been 

 the reverse of what it is. 



The materials of beds 1 and 2 seem to have been introduced from 

 above ; and the only portion of the accumulation which has the cha- 

 racter of a fluviatile deposit is the sandy bed No. 3. Numerous 

 specimens of the shingle are scattered over the upper platform of the 



* Ten metres above the level of the river. 



